


A Cross-Dimensional Tale for the Ages

by delta_maximus



Series: Multiverse Adventures [1]
Category: American Dragon: Jake Long, Avatar: The Last Airbender, Ben 10 Series, Danny Phantom, Generator Rex, Kim Possible (Cartoon)
Language: English
Status: In-Progress
Published: 2017-05-04
Updated: 2017-05-04
Packaged: 2018-10-27 20:49:36
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 2
Words: 3,482
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10816488
Author URL: https://archiveofourown.org/users/delta_maximus/pseuds/delta_maximus
Summary: When a new enemy comes forward that threatens every universe in existence, Ben Tennyson and his friends will have to lead a team of interdimensional heroes in their quest to defeat this enemy. Join Ben, Gwen, and Kevin as they travel to different universes and gather heroes such as Generator Rex, Kim Possible, the American Dragon and more in order to save all of existence.





	1. A Paradox in Time

**Author's Note:**

> Hello and thank you for reading my story. I do not own any of the franchises used in this story, all rights to their respective owners. The main characters of this story are Ben Tennyson, Danny Phantom, Kim Possible, Jake Long, Avatar Aang,and Generator Rex. Ben Tennyson's universe takes place right after the end of Ben 10: Ultimate Alien but before Ben 10: Omniverse (note: I will be omitting any content or continuity changes made in Ben 10: Omniverse, minus possibly a few aliens released in the show. All information will be from pre-Omniverse era.). Danny Phantom's universe will take place before the finale but will occur after he received his ice powers. Kim Possible's universe will take place after "So the Drama" but before the start of Season 4. Jake Long's, Avatar Aang's, and Generator Rex's universes will take place after the finales of their shows. Now that that's all out of the way, I hope you enjoy the story.

**Notes for the Chapter:**

> Hello and thank you for reading my story. I do not own any of the franchises used in this story, all rights to their respective owners. The main characters of this story are Ben Tennyson, Danny Phantom, Kim Possible, Jake Long, Avatar Aang,and Generator Rex. Ben Tennyson's universe takes place right after the end of Ben 10: Ultimate Alien but before Ben 10: Omniverse (note: I will be omitting any content or continuity changes made in Ben 10: Omniverse, minus possibly a few aliens released in the show. All information will be from pre-Omniverse era.). Danny Phantom's universe will take place before the finale but will occur after he received his ice powers. Kim Possible's universe will take place after "So the Drama" but before the start of Season 4. Jake Long's, Avatar Aang's, and Generator Rex's universes will take place after the finales of their shows. Now that that's all out of the way, I hope you enjoy the story.

**Ben Tennyson's Universe**

"AAAAHHHH!" Humongousaur yelled as he flew through the wall. Vulkanus jumped into the newly created hole in the wall and looked down at his handiwork.

"Had enough Tennyson, or do you want some more?" Humongousaur stood up and shook off the rubble.

"Funny, I was just about to ask you the same thing." Just as Vulkanus was about to respond a pink energy beam knocked him down from behind.

"Ow!" Vulkanus fell with a loud thud, being dazed by the unexpected attack.

"Took you guys long enough," Ben Tennyson said, looking at his two friends standing behind the fallen Vulkanus. Gwen Tennyson, his cousin, and Kevin Levin, his best friend, had been out on a date when Ben called Gwen and told her about Vulkanus attacking downtown Bellwood.

"Hey, don't blame us, blame the traffic." Vulkanus stood up groaning while taking a look at his attacker.

"Oh come on, not you two again. It's hard enough facing Tennyson alone!" The alien criminal had come to Earth hoping to rob an unsuspecting bank. The not-so-intelligent criminal failed to realize the bank he was robbing was two stores down from Mr. Smoothy's, Ben Tennyon's favorite restaurant.

"This may be a good time to give up," Gwen said as she prepared another energy blast.

"Give up? Ha, like that'll ever happen!" Humongousaur hit the Omnitrix symbol on his chest, creating a green light that temporarily blinded the others.

"Big Chill! Fine, if you won't give up then maybe you should just chill out." Big Chill flew towards Vulkanus while becoming intangible. Vulkanus tried to hit the Necrofriggian but failed, instead only freezing his arm in the process.

"Hey!" Big Chill landed next to Kevin and Gwen, tangible again.

"As much as I love messing around with Vulkanus I would like to finish my lunch sometime today," Kevin said as he leaned down to the pavement and absorbed the material, creating a thin layer of pavement that covered his entire body.

"Right, let's put him on ice." Just as the three teens were about to attack the Detrovite, a flash of light between the two groups stopped everyone in their tracks.

"Hello children!" The light died away to reveal the lab coat wearing time-traveler Professor Paradox standing before the heroes.

"Hey, who's this guy?" Vulkanus asked, confused as usual.

"No one you need to worry about. One moment Professor, I have to take out the trash." Big Chill became intangible and flew over Paradox and through Vulkanus, freezing his entire body. Vulkanus' eyes darted about, obviously in shock over his predicament. Ben landed back outside of the building with his friends, turning back into his human form as he landed. "Okay Professor Paradox, what seems to be the problem?"

"Oh nothing yet my dear boy. It's what isn't the problem that's the problem."

* * *

 The group relocated to Mr. Smoothy's after Gwen called in the Plumbers to pick up Vulkanus. Paradox didn't elaborate on what he had said earlier, only making small talk and offering everyone a gumball as Kevin drove to their usual hangout. It was only after everyone sat down and ordered a frozen beverage that Paradox began to explain his cryptic message.

"As you are all aware, this universe is not the only one in existence. There is in fact a multiverse that exists which is made up of multiple universes, all separate entities yet similar to one another." The group nodded in understanding, having heard this description from Paradox before. "However, our multiverse is not the only multiverse in existence. There are in fact other multiverses that are not so similar to our own." Kevin gave Paradox a blank stare.

"And now you lost me."

"Understandable. I will try to break down all of existence as simplistically as possible." Suddenly the Mr. Smoothy shop dissapeared, as did everything else around the shop. Ben, Gwen, and Kevin were standing in the middle of what looked like space, only distorted.

"Where are we?" Gwen asked, her eyes darting all about the teens' new environment.

"We are currently in a pocket dimension that exists between the multiverses. If you will look over to your left, or what would be your left if directions existed in this world, you will see our entire multiverse and it's separate universes." The teens did as instructed and looked to see hundreds of what looked like blue swirls swimming around the empty space. "Now if you look to your right you will see another multiverse that is not related to our own, with its own unique universes swimming about." Repeating their previous action, the group looked and saw hundreds of green swirls moving about the empty space, occasionally colliding with each other.

"So our multiverse, our dimension, is over there, and another dimension, or another multiverse, is over there?" Ben asked.

"Ah yes, very good Ben. You always did have a knack for understanding the time-space continuum. Now, unlike different universes within a set multiverse, different dimensions are not similar look-a-likes of each other. Each dimension is its own reality, containing its own universes within it which are similar yet different to each other. If I remember correctly Ben, you yourself obtained the extremely rare opportunity to travel to a parallel dimension." Ben nodded, remembering his adventure in creepy EVO land when he got pulled into Rex's universe, a place where everyone was infected with nanomachines that could turn people into freaky monsters at any time. He had told Gwen and Kevin all about it after he returned, though they weren't that surprised by the story considering their daily adventures. "And you all have journeyed to the Null Void before, a dimension quite different than any other I have ever seen."

"Professor Paradox, if the Null Void is its own dimension then why is it so easy for us to access it? You said it was extremely rare for Ben to visit another dimension." Paradox chuckled at Gwen's question. She always was a clever girl.

"Very good question, young Gwendolyn. You see, the Null Void is particularly close to your dimension compared to others. It itself is also broken up into smaller, more condensed universes which are connected to the universes found in our own multiverse. That is why you will never find an alien criminal from another universe in your Null Void. However, on rare occasions, other universes have been able to breach into the Null Void, as shown when Rex's brother Caesar sent his Alpha nanite there in order to remove it from his own universe." Ben and Kevin seemed confused from Paradox's explanation but Gwen understood the gist of it.

"Not that I don't love this little science lesson but I'm kinda wondering why you're telling us all this in the first place." Kevin always was one to get to the point.

"Very well. I'm afraid the multiverse as I know it, and as you don't know it, is in danger, or rather, it will be in danger."

"I don't follow," Ben said as he turned his head in confusion.

"Every multiverse, not just our own, is in danger. There has never been such a threat like this before, yet I'm afraid it is inevitable. In fact, we already lost this battle once before." The young group's faces turned to shock at Paradox's words. "Yes, you all fought against this evil before, along with other cross-dimensional heroes and lost. The entire cross-dimensional multiverse was destroyed, obliterated. Luckily, I was able to find one last path back in time to before the emergence of this threat. Now, I am gathering every hero I can in order to face it. It is our only hope in saving not just our multiverse, but every multiverse."

"Well, if this is as big as you say it is, why not collect every hero from every universe, like having multiple Bens," Gwen suggested.

"I'm afraid that would put a bit too much strain on the multiverse. You see, it is dangerous enough crossing dimensions like this as we are. It is one thing to have two universes within the same multiverse coincide. That is damage that can be easily repaired. However, cross-dimensional travel is its own demon and is only supposed to be committed under the most dire circumstances. The time-space continuum is already fragile after I traveled back before its destruction. Bringing together multiple Ben Tennysons, for example, as well multiple versions of other heroes would completely distort the cross-dimensional universe and cause a ripple that would completely devastate life as we know it. I can only bring together the original versions of each hero, the Prime universes from which the other universes sprung. Even with that I am limited to only accessing approximately six or seven different dimensions. Entering any more would cause the multiverse to collapse in on itself."

"This is all so intense. How can we help?" Ben was ready to save the universe just as he and his friends had done many times before.

"Well, first I could use some assistance in recruiting your future teammates in this endeavor. I could recruit them myself but I think it would be better if their team leader met them and explained the situation first hand." Paradox noticed Ben's surprised expression. "Ah yes, did I forget to mention? I'm placing you in charge of our little inter-dimensional team. Although most of the other heroes have faced situations involving time travel and universal travel before, you have the most experience when it comes to these situations. I feel you are our best hope in leading us to victory."

"Are you sure? I mean, I know I've saved the universe before and stuff, but this is on a whole other level." Gwen placed a reassuring hand on Ben's shoulder.

"It'll be okay, Ben. You'll have us by your side, and together we can win this."

"She's right. We're not going to let you face this all by yourself Tennyson." Ben smiled at his two friends, happy to have them by his side once again. "Okay Paradox, I'm ready. We're ready."

Paradox nodded his head and smiled. "Very good, children. Then, let us begin!"


	2. Aliens and Ghosts and Blasters, Oh My!

**Notes for the Chapter:**

> I do not own any of the franchises used in this story, all rights to their respective owners. Hope you enjoy the story!

 

**Unknown Universe**

Ben, Gwen, and Kevin shielded their eyes as the white light began to die down. Paradox had just transported them somewhere again, only this time they were in a place with solid ground. Ben looked around and saw they had arrived in a town that reminded him of Bellwood, yet he knew this place was different.

"We're in another dimension, aren't we?" Gwen asked.

"Correct my dear. We are currently in a town known as Amity Park in a dimension not too far from your own."

"So what's so special about this place?" Kevin asked as he took in his surroundings. He noticed the group was standing outside a restaurant called The Nasty Burger. "And what's with the names here, anyway?" Paradox walked in front of the group and looked at his pocket watch.

"To answer your first question, this place is not too special. Just your average, ordinary town, except for one thing." Paradox was cut off by screams coming off in the distance. Gwen looked down the street and saw that the screams seemed to be originating from a high school not too far from them. "You may want to go check on that."

That's all Ben needed to here. He touched the face plate of his Omnitrix, causing the lid to slide off and the Omnitrix core to pop up. A hologram of his alien Rath came up.

"I'd better pick someone a little bit more stealthy until we see what this place is about." Ben cycled through his aliens till he found one that would suffice. Ben slammed down the Omnitrix core and transformed in a flash of green light. "Ghostfreak!"

"Splendid choice, Benjamin. You really do have an innate knowledge when it comes to inter-dimensional travel." Ben was going to ask what Paradox meant but decided against it in favor of checking out what was going on at the high school.

"I'll fly ahead and see what's going on. You guys make sure any bystanders get out of here and then meet me there." Ghostfreak flew off after giving his instructions, heading towards the high school. Gwen and Kevin set to work making sure anyone on the streets got inside safely or stopped going near the high school. Paradox chuckled to himself and took another look at his pocket watch.

"Well, this will certainly be interesting."

* * *

Ghostfreak flew into the high school, phasing through the outer wall and ending up in what looked like a Chemistry classroom. The room was empty, though the left behind books and crumbled up pieces of paper told Ben this room was just recently evacuated. Ben flew out into the hallway, trying to find the source of the screams from earlier. Ben finally found a few girls standing near their lockers talking to each other, obviously unaware of whatever the situation currently was.

"Hey, are you guys okay?" Ben asked. The girls all turned and shrieked, crying "Ghost!" before running. "Well that didn't go as planned."

Suddenly two figures flew out of the nearby wall and landed on the hallway floor. One of them, a humanoid robot with green hair and a large gun strapped to his arm, was standing over the other, a young teenage boy with white hair and a black jumpsuit.

"It's over, Ghost Child!" The robot aimed its blaster at the boy and began to charge it up. Ghostfreak slammed into the robot, sending it flying into the wall.

"Are you okay?" Ghostfreak asked the boy. The kid stood up slowly, somewhat perplexed that Ghostfreak helped him.

"Yeah, thanks for the help. Who are you?"

"The name's Ghostfreak. How about you?" The boy was about to respond when he was hit by an energy blast.

"Ha, direct hit!" A large man in an orange jumpsuit smiled triumphantly, holding a large cannon that Ghostfreak assumed was just used to hit the boy. "One down, one to go!" The man aimed the large gun at Ghostfreak.

"Oh come on. I'm not in this dimension for five minutes and I'm already getting shot at." The man fired his cannon but the energy blast never made it to Ghostfreak. A pink energy shield formed in front of him, shielding him from the attack. "Thanks Gwen!"

Gwen and Kevin had just made it into the hallway when they saw the young boy get shot down by the orange jumpsuit man. The man turned and noticed Gwen and Kevin.

"You kids need to get out of here! These ghosts are dangerous."

"Did he just say ghosts?" Kevin asked. Before anyone could answer, the robot from before got back on his feet and walked towards Ghostfreak.

"I don't know who you are but no one interferes with my hunt!" The robot raised his blaster arm at Ghostfreak, the blaster's light returning to life.

"I think that's enough for one day Skulker!" The boy from before was now floating next to Ghostfreak holding what looked like a soup thermos. _Is he going to make him something to eat?_ Ben thought. The kid aimed the thermos at the robot and fired out a blue beam that engulfed it entirely.

"NO!" it screamed as it flew into the thermos.

"Hey, that's my catch Ghost Kid! Now you're going to get it!" The man aimed his gun at the boy again. He charged up the gun and was about to fire when the gun suddenly died down. "Stupid thing must be out of juice." The boy took that as his cue to leave.

"Follow me!" he said to Ghostfreak as he flew up into the ceiling. Ghostfreak followed while Gwen and Kevin headed back out the way they came in.

* * *

The boy led Ghostfreak into an alleyway just around the corner from the school. The two landed next to a couple of trash bins, making sure they weren't seen by any other people walking the streets. Ben knew Gwen and Kevin would be here soon, having made sure they saw him fly out of the school.

"Thanks for your help back there!" the boy said, beaming at the Ectonurite.

"Don't mention it. I never did get your name though."

"Oh, sorry about that. I'm Danny, Danny Phantom." _Danny Phantom? Amity Park? Nasty Burger? I'm pretty certain that high school was called Caspar High. This place really needs better names,_ Ben thought to himself. "I've never seen a ghost like you around before."

"That's because I'm not a ghost, you see. Let me show you." Ghostfreak slammed the Omnitrix in the middle of his chest, and instead of a white ghost with a single green eye now stood a sixteen year old American boy with brown hair.

"No way! You're a Halfa too?"

"A what-a? I have no idea what that is. My name is Ben Tennyson. I'm a human."

"A human? But you were just a ghost, weren't you?" Ben chuckled at Danny's question.

"I guess you could say that, but that wasn't really a ghost. I was actually an alien. You see, this watch I have on, it's called the Omnitrix. It lets me turn into a bunch of different aliens, one of which looks and acts like a ghost. Is that what you are, a ghost?" Danny was somewhat surprised by his new friend's statement. He found it hard to believe that someone could turn into aliens. Then again, he was the half-ghost here.

"I'm half-ghost, half-human. Watch this." Ben watched as two blue rings formed around Danny's waist and flew in opposite directions. Where the white haired, black jumpsuit wearing ghost was now stood a black haired boy with a white t-shirt and blue jeans. "My name is Danny Fenton."

"Good to see you're both getting along well!" Paradox had appeared from behind Ben. Gwen and Kevin appeared with him, the two having been picked up by him on his way here.

"Who are these guys?" Danny asked, fearful of these strangers. Ben assumed Danny's identity as a superhero wasn't well-known here in ghost land.

"These are my friends. This is my cousin Gwen, my friend Kevin, and my uh, mentor, Professor Paradox." Ben pointed to each individual as he introduced him or her.

"Mentor, hm? I quite like the sound of that. Any who, now that introductions are out of the way I'm afraid we must get to the dire situation part. Young Daniel Fenton, we are in need of your assistance. There is a threat to our world as well as your own. As you may or may not have guessed by now, we are not from this universe. We come from one near your own and are gathering heroes together in order to fight against this threat. If we fail, then everything will be lost. Will you help us?" Danny pondered over what Paradox told him, deep in thought over what he heard.

"Will I have to leave my home? You know, Amity Park? I can't leave it unprotected while I'm gone."

"Ah yes, always caring about your loved ones. It's one of the reasons why I chose you for this quest. Yes, you will have to leave but you will not be missed. Time travel is a funny thing but if all goes well it will be like you never left. You'll be gone for one instant and then reappear in the next. Plus, you won't be going alone." Danny cocked his head curiously at Paradox's comment. "Oh, didn't I tell you? You're friends will be joining you. What were their names again?"

"Sam and Tucker?" Paradox snapped his fingers.

"That's them! Yes, they will make quite an asset to our team." Danny shook his head.

"No, I don't want them coming! They could get hurt, or worse."

"Like we're actually going to let you go save the entire universe all by yourself, dude." Danny was shocked to see his friends Sam Manson and Tucker Foley walking into the alleyway.

"We might have grabbed them on the way here," Kevin explained.

"We're in this together, like always. If you're going to go out and fight, then we're coming too!" Sam told him. Danny wanted to argue but he knew their minds were made up.

"Okay, I guess I don't have a choice. Thanks you guys."

"Very good! I stopped at your house, Daniel, and picked up some off your parents ghost hunting equipment. I believe it will be useful in our upcoming battle. And don't worry, you'll be seeing Amity Park again sooner than you think." Something about the way Paradox said that gave everyone an ominous feeling. "Time to go!" A portal opened up behind Paradox, which he walked into. Everyone else shrugged and then followed, wondering what universe they would find themselves in next.


End file.
